PMS study pans popular prescription.

PMS study pans popular prescription

Many women suffering the emotional and physical anguish of premenstrual syndrome (PMS) look to the hormonal drug progesterone for relief. But according to the first large-scale test of progesterone's effectiveness in PMS, they might just as well take a placebo.

In a group of 168 PMS-afflicted women, placebo vaginal suppositories relieved PMS symptoms at least as well as suppositories containing progesterone, reports an interdisciplinary team of researchers from the University of Pennsylvania and Hahnemann University in Philadelphia.

"This is the first study that has a large enough sample size and the statistical power to say with certainty that the progesterone treatment is useless, that you can save the money and try other therapy," asserts coauthor Karl Rickels, a psychiatrist at the University of Pennsylvania.

Among U.S. women of childbearing age, as many as 10 percent suffer from PMS, Rickels says. PMS typically flares up only during the last week of the menstrual cycle, with symptoms severe enough to interfere markedly with daily routines. Symptoms may include depression, anger, sudden bouts of tearfulness, food cravings and headaches, among others. Though the cause remains unknown, physicians widely prescribe progesterone on the hypothesis that PMS stems from an abnormally high ratio of estrogen to progesterone late in the menstrual cycle.

Each woman in the Philadelphia study received either placebo or progesterone vaginal suppositories on days 16 through 28 of the menstrual cycle. Neither the women nor the researchers knew which treatment went to whom. During the next menstrual cycle, patients received double doses of their respective treatments. The two groups then switched treatments and repeated the two-month regimen.

Overall, patients did show some improvement during the first two months of the study, but the researchers found essentially no difference between the groups, regardless of dose. Women who then switched from placebo to progesterone actually experienced a worsening of symptoms, while the new placebo recipients showed no change, the team reports in the July 18 JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION.

"The study is solid, but that's not saying we might not in some cases find women for whom progesterone or its derivatives might work. But certainly not in the broad category. If it works, I don't know why it works," comments Florence P. Haseltine, a reproductive endocrinologist at the National Institutes of Health.

Pharmacist David Myers remains a progesterone proponent. "We have patients who have been on progesterone for 10 years who have had too dramatic a change in their life to call it a placebo effect. No one can tell me that a placebo effect can last 10 years," he says. Myers is vice president of Madison (Wis.) Pharmacy Associates, Inc., which specializes in PMS treatment.

Rickels says he suspects "there is a much larger emotional than physical component behind PMS symptoms." He and others are now conducting preliminary studies using antidepressants and appetite suppressants to treat the monthly menace.